Java AbstractSequentialList isEmpty()方法及实例

Java中 AbstractSequentialList 的 isEmpty() 方法用于检查该AbstractSequentialList是否为空。它返回一个布尔值，说明这一点。

语法

public boolean isEmpty()

参数： 该函数没有参数。

返回： 该方法返回一个布尔值，说明AbstractSequentialList的这个实例是否为空。

下面的例子说明了AbstractSequentialList.isEmpty()方法。

例1 :

// Java code to demonstrate the working of
// isEmpty() method in AbstractSequentialList
  
import java.util.*;
  
public class GFG {
    public static void main(String[] args)
    {
        // creating an AbstractSequentialList
        AbstractSequentialList<Integer> arr
            = new LinkedList<Integer>();
  
        // using add() to initialize values
        // [1, 2, 3, 4]
        arr.add(1);
        arr.add(2);
        arr.add(3);
        arr.add(4);
  
        // print AbstractSequentialList
        System.out.println("AbstractSequentialList: "
                           + arr);
  
        // Check if AbstractSequentialList is empty
        // using isEmpty() value
        System.out.println("Is AbstractSequentialList empty? "
                           + arr.isEmpty());
    }
}

输出。

AbstractSequentialList: [1, 2, 3, 4]
Is AbstractSequentialList empty? false

例2 :

// Java code to demonstrate the working of
// isEmpty() method in AbstractSequentialList
  
import java.util.*;
  
public class GFG {
    public static void main(String[] args)
    {
        // creating an AbstractSequentialList
        AbstractSequentialList<String> arr
            = new LinkedList<String>();
  
        // print AbstractSequentialList
        System.out.println("AbstractSequentialList: "
                           + arr);
  
        // Check if AbstractSequentialList is empty
        // using isEmpty() value
        System.out.println("Is AbstractSequentialList empty? "
                           + arr.isEmpty());
    }
}

输出。

AbstractSequentialList: []
Is AbstractSequentialList empty? true